Method patchValue

packages/forms/src/model/form_array.ts:367–386

* Patches the value of the `FormArray`. It accepts an array that matches the * structure of the control, and does its best to match the values to the correct * controls in the group. * * It accepts both super-sets and sub-sets of the array without throwing an error. * * @usageNotes

(
    value: ɵFormArrayValue<TControl>,
    options: {
      onlySelf?: boolean;
      emitEvent?: boolean;
    } = {},
  )

   * the {@link AbstractControl#updateValueAndValidity updateValueAndValidity} method.
   */
  override patchValue(
    value: ɵFormArrayValue<TControl>,
    options: {
      onlySelf?: boolean;
      emitEvent?: boolean;
    } = {},
  ): void {
    // Even though the `value` argument type doesn't allow `null` and `undefined` values, the
    // `patchValue` can be called recursively and inner data structures might have these values,
    // so we just ignore such cases when a field containing FormArray instance receives `null` or
    // `undefined` as a value.
    if (value == null /* both `null` and `undefined` */) return;

    value.forEach((newValue, index) => {
      if (this.at(index)) {
        this.at(index).patchValue(newValue, {onlySelf: true, emitEvent: options.emitEvent});
      }
    });
    this.updateValueAndValidity(options);
  }

  /**
   * Resets the `FormArray` and all descendants are marked `pristine` and `untouched`, and the